Clinical Spectrum of Neonatal Encephalopathy and the Role of CK-MB Assay in Transient Myocardial Ischaemia in Neonates with Hypoxic Ischaemic Encephalopathy: A Prospective Cohort Study

Abstract

Introduction: Significant advancements have been made in the field of perinatal medicine through the use of newer monitoring technologies. However, birth asphyxia continues to cause prolonged hospitalisation due to multiple organ dysfunction and unfortunately, sometimes results in death. An elevation of the serum Creatine Kinase Myocardial Bound (CK-MB) fraction in myocardial ischaemia could indicate exposure to asphyxia and shock in neonates. Aim: The aim of this study was to examine the clinical spectrum of Neonatal Encephalopathy (NE) and investigate Transient Myocardial Ischaemia (TMI) in neonates with Hypoxic Ischaemic Encephalopathy (HIE) using CK-MB assay at birth, 24 hours, and 72 hours. Materials and Methods: A prospective clinical study was conducted in the Neonatal Intensive Care Unit (NICU) at a Tertiary Care Hospital in Tamil Nadu, India. The study duration was eight months, from January 2014 to August 2014. A total of 70 term neonates admitted with NE symptoms were included. Among them, 65 babies with evidence of asphyxia, such as an Appearance, Pulse, Grimace,Activity and respiration (APGAR) score less than 3 at five minutes, heart rate less than 60 Beats Per Minute (bpm), meconium-stained amniotic fluid, or the need for positive pressure ventilation for more than one minute, were evaluated for TMI. Myocardial involvement was assessed through clinical evaluation, chest X-ray (CXR), Electrocardiogram (ECG), Echocardiography (ECHO), and CK-MB assay at birth, 24 hours, and 72 hours. Statistical analysis was performed using Epi Info software version 7.0. Results: The mean Gestational Age (GA) of the study participants was 38.97±1.31 weeks. During the study period, 70 babies were admitted with NE symptoms, and HIE was the cause of encephalopathy in 65 babies. Other causes included hypoglycaemia, intraventricular haemorrhage, and bilirubin encephalopathy. Meconium staining of amniotic fluid was the most common intrapartum event in HIE babies. The survival rate in encephalopathy cases was 28.57%. Shock and respiratory failure were common complications in HIE, representing 46.15% and 44.61% respectively. Cardiomegaly in CXR, ST depression in ECG, Tricuspid Regurgitation (TR) in ECHO, and elevated CK-MB were commonly detected in babies with TMI associated with HIE. Conclusion: NE caused by HIE has a high mortality and morbidity rate. 83.3% of asphyxiated babies with shock had elevated CK-MB levels at birth, but the CK-MB values at 24 hours and 72 hours were not significantly elevated.